栉孔扇贝(♀)×虾夷扇贝(♂)杂交子代胚后发育过程中遗传构成变化研究

Research on genetic variation of hybrid scallop from Chlamys farreri ♀× Patinopecten yessoensis ♂ during post-embryo growth

采用RAPD和GISH技术对栉孔扇贝(♀)和虾夷扇贝(♂)杂交子代胚后发育4个重要时期(担轮幼虫期、D形幼虫期、壳顶幼虫期和眼点幼虫期)的遗传构成进行了检测。在RAPD检测中,50条随机引物在亲贝中共扩增出35条栉孔扇贝的特异条带和28条虾夷扇贝特异条带,其中栉孔扇贝特异条带在杂交子代4个时期出现的条数分别为:担轮幼虫期21条、D形幼虫期19条、壳顶幼虫期23条和眼点幼虫期23条;而虾夷扇贝特异条带在杂交子代4个时期出现的条数分别为:17、16、1和1。GISH结果表明,杂交扇贝在担轮幼虫期和D形幼虫期均继承了来自父母本遗传物质,而在壳顶幼虫期和眼点幼虫期未检测到来自父本的遗传物质。结果表明,杂交子代遗传结构在进入壳顶幼虫期时发生重大改变,大部分父本遗传物质从杂交贝基因组中丧失。

RAPD analysis and genome in situ hybridization （GISH） were applied to research into the genetic variation of the Chlamys farreri ♀× Patinopecten yessoensis ♂ hybrid scallop larvae during the four life-history stages （trochophore,D-shaped larvae,umbo-stage larvae and eye-spot larvae）. For RAPD analysis,50 random primers were used and 35 C. farreri specific bands and 28 P. yessoensis specific bands were detected in the broodstock. Different numbers of C. farreri specific bands were found in the hybrid during the four lite-hastory stages, and the numbers were： 21 in trochophore,19 in D-shaped larvae,23 in umbo-stage larvae, and 23 in eye-spot larvae. The numbers of the P. yessoensis specific bands found during these stages were 17,16,1 and 1, respectively. Meanwhile,the result of GISH analysis indicated that the hybrid scallop separately inherited one set of chromosomes （n= 19） from both C. farreri and P. yessoensis broodstock during both the trochophore stage and the D-shaped larvae stage, while no P. yessoensis germ plasm was founded in the umbo-stage larvae and the eye-spot larvae. It was found that,a big transformation of the genetic composition of the hybrid happened in umbo-stage larvae when most of the paternal germ plasm was lost in the genome of the hybrid scallops.